feat(game): void unreplayable games as a draw instead of erroring

A committed move that becomes illegal under a tightened rule (the single-word
connectivity fix) makes engine replay fail, which left such games unopenable —
an empty screen and an 'illegal play' error. Now the first open closes the game
gracefully as a draw (engine.EndAborted -> end_reason 'aborted', no winner),
preserves the journal, and surfaces an impersonal organizer note at the end of
the move history and in the GCG export.

- engine: EndAborted + Abort() (draw, no rack adjustment; winner -1).
- service: replay aborts on ErrIllegalPlay; liveGame persists the void once
  (lazy, on open); GameState re-reads for the settled view.
- store: VoidGame finishes the game and stamps a draw without a journal row.
- migration 00002: allow end_reason 'aborted'.
- ui: organizer note under the history grid; i18n en/ru.
- docs: ARCHITECTURE 6/9.1, FUNCTIONAL(+ru), PRERELEASE MW3.

backend/internal/game/gcg_test.go

@@ -61,6 +61,21 @@ func TestWriteGCG(t *testing.T) {
 	}
 }
 
+func TestWriteGCGAbortedNote(t *testing.T) {
+	g := Game{
+		ID:          uuid.MustParse("00000000-0000-7000-8000-000000000002"),
+		Variant:     engine.VariantErudit,
+		DictVersion: "v1",
+		Players:     2,
+		Status:      StatusFinished,
+		EndReason:   "aborted",
+	}
+	out := writeGCG(g, []string{"Alice", "Bob"}, nil)
+	if !strings.Contains(out, "#note [organizer]") {
+		t.Errorf("aborted game GCG missing the organizer note:\n%s", out)
+	}
+}
+
 func TestGCGTilesUppercasesCyrillic(t *testing.T) {
 	if got := gcgTiles([]string{"к", "о", "т", "?"}); got != "КОТ?" {
 		t.Errorf("gcgTiles = %q, want КОТ?", got)